The family of chemicals containing allyl groups is important both to the human sense of smell and taste, and to the fragrance and flavor business community at large. Regardless of whether the resulting compound is aliphatic or aromatic, alicyclic or containing heteroatoms, this short (three-atom) carbon chain seems to contribute a structural olfactophore. The organoleptic span of allyl-containing ingredients covers the range between green and galbanum fruity notes, from floral-rosy to herbal to spicy to pungent, garlicky and green onionlike with meaty nuances.
First in this category are the simple aliphatic esters, such as allyl acetate (CAS #591-87-7), which have a diffusive, pungent, gassy odor that is fruity on dilution, and allyl amyl glycolate (F-1; AAG; CAS #67634-00-8), a strongly fruity material with a green, herbal odor, galbanum connotations, and apple and pineapple notesa.
The allyl group can also be connected to an alicyclic ester, as in the case of allyl cyclohexane acetate (CAS #4728-82-9), which results in a sweet, ripe, pineapplelike odor with a green waxy nuance. Allyl cyclohexane propionate (CAS #2705-87-5), a fruity, pineapple, waxy odor with green sweet apple nuances, is another example in this series (F-2).